[back] [prev] [next] [index] [root]

 


FFEToElt

Returns a canonical representative of a finite field element viewed as a representative of a class of algebraic numbers.

Syntax:

a := FFEToElt( f, p);

finite field element
  f  
ideal
  p  
must be prime
algebraic number or integer
  a  
interpreted as algebraic number

See also:  IdealResidueField, IdealResidueFieldIsomorphism, EltToFFE

Description:

This is a inverse function of EltToFFE, and a embedding O / {\goth{p}} rightarrow O. The prime ideal must not lie over a number which divides the degree of the order.


Example:


kash> O := OrderMaximal(Order(Poly(Zx,[1,4,1,-4,-3,7])));
Generating polynomial: x^5 + 4*x^4 + x^3 - 4*x^2 - 3*x + 7
Discriminant: 28442269 

kash> p := Factor(7*O)[1][1];
<7, [0, 1, 0, 0, 0]>
kash> b := Elt(O,[3, 1,5,1,8]);
[3, 1, 5, 1, 8]
kash> n := EltToFFE(b, p);
3
kash> FFEToElt(n, p);
> 3


<- back[back] [prev] [next] [index] [root]